Audio signalling device

ABSTRACT

An audio signalling unit including a housing body made of molded synthetic plastic material and having an end wall and transversely extending side walls defining an opening into the housing body. This housing body has various positioning shoulders and locator means molded integrally therewith for supporting and positioning a vibratable reed, contact carrying plates and a coil all forming a buzzer which vibrates the reed. The opening into said housing body is closed by a vibratable metal buzzer-forming diaphragm bridging the side walls of the housing body and coated on the outside thereof with an insulating material so that no electrical contact can be made with the metal body of the diaphragm from the outside of the housing and the outer surface thereof is insulated from the electrical conponents inside the housing.

0 1' il1ted States atent 1 1 1 l Youhanaian Sept. 18, 1973 AUDIO SIGNALLING DEVICE v [57] ABSTRACT [75] I inventor: Lawrence A. Youhanaian, Des

1 Plaines,lll.

An aud1o signallmg unit mcludmg a housmg body made [73] Assignee. Littelfuse' Inc Des Flames 1 of molded synthetic plastic material and having an end wall and transversely extending side walls defining an [22] Filed: Sept. 10, 1971 I opening into the housing body. This housing body has various ositionin shoulders and locator means [21] Appl' 179387 molded i tegrally t herewith for supporting and positioning a vibratable reed, contact carrying plates and a 52 1 US. Cl. 340/3ss,'340/402 coil all forming a buzzer which vibrates the reed- [5 1] Int. Cl. Gl0k 9/12 pening into Said housing body is closed by a vibratable [58] Field of Search 340/388, 402, 403, metal buzzer-forming diaphragm bridging the side walls 340/384 R of the housing body and coated on the outside thereof with an insulating material so that no electrical contact 5 Referen es Ci can be made with the metal body of the diaphragm UNITED STATES PATENTS from the outside of the housing and the outer surface 3 653 039 3/1972 Home 340/388 thereof is insulated from the electrical conponents in- 3:6l8:080 11/1971 Frey 340 402 We the Imusmg' 3,562,748- 2/1971 Wetzel et al... 340/388 3,656,156 '4/l972 Berns 340/388 Att0rney-Wallenstein,

Strampel 14 Claims, 10 Drawing Figures PATENTEDSEP18I975 SHEET 2 BF 2 1' N VEN r0 R lawns/m 4; Vow/44 4mm AUDIO SIGNALLING DEVICE BACKGROUND OF THE INVENTION purpose described above there is included a base of insulating material having supported thereon the various electrical components forming a buzzer, including a magnetic field producing coil, metal terminals,-a contact plate and a vibratable reed made'of metal or the like. The reed carries a-magnetic member initially attracted to the core of the coil when the same is energized and a contact which controls the flow of current to the coil which is interrupted when the reed is attracted by the coil,t o cyclically effect vibration of the reed. A cup-shaped m'etal cover member is secured around the periphery of the base and serves both as a closure housing for the buzzer and a vibratable wall struck by a striker member also carried by the vibrating reed of the buzzer. To minimize shock and short circuit hazards, thestriker member was made of glass or other similar insulating material.

One of the objects of the invention is to provide a buzzer of the above-described type where an outer wall of the housing forms a vibratable wall for the buzzer and wherein the component parts of the buzzer contained within the housing can be more easily mounted and positioned within thebuzzer housing during the manufacture thereof.

Another object of the invention is to provide a buzzer v of the type described wherein the entire reed and the magnetic member, contact and striker member carried thereon may be made of metal or other conductive material and wherein the vibratable wall of the buzzer may be made of metal and yet be devoid of any significant shock or short circuiting hazards.

SUMMARY OF THE INVENTION Inaccordance with one of the features of the inven- In the most desirable form of the invention just described, the open ended housing body closed by the vibratable wall has positioning shoulders and locator means molded as an integral part thereof for enabling the various parts of the buzzer to be readily located and supported prior to final anchoring and soldering operations.

The above and other objects, advantages and features of the invention will become apparent upon making reference to the specification to follow, the claims and the drawings wherein:

DESCRIPTION OF THE DRAWINGS FIG. I is an elevational view of a buzzer unit of the present invention mounted in an opening within a wall and removably receiving a socket connector unit which electrically interconnects the buzzer unit to a source of voltage and control switch means;

FIG. 2 is a sectional view through the socket connector unit containing portion of FIG. 1, taken along section line 2-2 therein;

FIG. 3 is a fragmentary sectional view through the assembly of FIG. 1, as seen along a plane 3-3 therein and showing the manner in which the buzzer unit is mounted on the wall shown therein;

FIG. 4 is a rear view of the buzzer unit shown in FIG.

FIG. 5 is an elevational view of the buzzer unit of FIG. 4 withthe vibratable closure wall portion thereof removed from the buzzer unit to expose the interior of the buzzer unit housing;

FIG. 6 is an enlarged sectional view through the buzzer unit shown in FIG. 5, taken along section line 6-6 therein with with the vibratable closure wall mounted in place;

FIG. 7 is an enlarged sectional view through the buzzer unit shown in FIG. 5,taken along section line tion, in ,a buzzer of the general type previously described all of the outer walls of the buzzer housing including the vibratable wall struck by the striker member of the vibrating reed have exposed surfaces made of insulating material, so that no electrical contact can be readily externally made to'components inside of the housing except through electrical terminals thereof which may project therefrom. The vibratable wall forming one of the outer walls of the housing is made of metal to provide an efficient'sound generating diaphragm, and the outer surface of the metal vibratable wall is coated with an insualting material to insulate the outside of the same from any conductive parts or surfaces on the inside of the housing. The'other walls of the housing are most desirably made of molded synthetic plastic material and the insulating material coated metal vibratable wall most desirably bridges and is supported by insulating side walls of the housing de-' fining the opening into the housing through which the parts making up the buzzer are passed initially into the housing.

7-7 therein with the vibratable closure wall mounted in place;

FIG. 8 is an enlarged sectional view through the buzzer unit shown in FIG. 5,taken along section line 8-8 therein;

FIG. 9 is an enlarged sectional view through the buzzer unit housing with all parts normally contained therein removed; and 7 FIG. 10 is a greatly enlarged sectional view through the vibratable wall of the buzzer unit housing.

DESCRIPTION OF THE PREFERRED EMBODIMENT Refer now to FIGS. l3 showing the assembly of a buzzer unit 2 of the invention mounted in a support wall 4 and carrying a removable socket connector unit 6. A pair of insulated conductors 8-8 extend from the socket connector unit 6 and terminate in terminal strips 10-10 which connect to a source of energizing voltage (not shown), such as the 12 volt battery of an automobile, and a control switch which controls the operation of the buzzer unit 2. The socket connector unit 6 has a housing 7 made of synthetic plastic insulating material and having a pair of parallel extending sockets 6a-6a in which tubular terminals 6b--6b are mounted for removably frictionally receiving terminals I242 projecting through openings in a side wall 16 of a housing 18 of the buzzer unit 2. The housing 7 has a recess or channel 6c into which extends a socket holding extension 14 projecting from the side wall 16 of the buzzer unit housing 18. The socket unit holding extension 14 has an opening 14a into which extends a locking detent 17 which removably holds the socket connector unit 6 in a fixed position upon the buzzer unit 2.

The buzzer unit housing 18 has an anchoring extension 20 projecting from a side wall 16 of the housing opposite the side wall 16 previously described. The mounting extension 20 is of a size and shape to fit loosely within a D-shaped opening 21 formed in the mounting wall 4 when the buzzer unit is held in one orientation, and to frictionally lock within the opening 21 when the buzzer unit 2 is turned 90 from the latter orientation.

The buzzer unit housing 18 most desirably comprises a main housing body 180 having a rear or end wall 24 from the margins of which transversely extend the aforementioned side walls 16-16 and side walls 22-22. The side walls 16-16 and 22-22 define an opening 26 into the housing body 18a through which various parts of the buzzer unit to be described are inserted into the housing body 18a when the buzzer unit is fabricated. The various parts of the housing body 18a above described including the rear or end wall 24, the side walls 16-16' and 22-22' and the extensions 14 and 20 are formed as a single molded part made from a suitable synthetic plastic insulating material.

The opening 26 into the housing body 18a is closed by a vibratable closure wall 18b which bridges the side walls 16-16' and 22-22' of the housing body 18a. The vibratable closure wall 18b forms a vibratable diaphragm for the buzzer unit 2 and therefore desirably is made of relatively thin metal. As best shown in FIG. 10, the vibratable closure wall 185 has applied to the outer side thereof a coating 25 of insulating material so that all outer surfaces of the buzzer unit 2 except the projecting terminals 12-12 are electrically insulated so no electrical connections to any parts within the buzzer unit can be made from outside of the buzzer unit except through the terminals 12-12. The vibratable closure wall 18b has an inwardly dished main central portion terminating in a sharply inwardly projecting nose portion 30 at the center thereof. The vibratable closure wall 18b has a reversely bent peripheral portion 31 abutting shoulders 33 (FIG. 7) formed by the edges of the side walls 16-16' and 22-22' of the housing body 18a and snap fitting within an undercut portion 34 (FIG. 7) of the side walls.

As best shown in FIG. -8, the buzzer unit housing 18 encloses various components forming an electrical buzzer, namely a coil assembly generally indicated by reference numeral 35 and including coil windings 35a wound on a coil frame 35b and a cantilevered vibrating reed 37 including a main spring metal body 370 carrying a combination striker and magnetic member 37b at the free end thereof which strikes the nose portion 30 of the vibrating closure wall 18b when the buzzer is operating. As best shown in FIG. 7, the reed 37 further includes an electrical contact 37c adapted to make electrical contact with a stationary contact 39 carried on the end ofa metal contact plate 41. The coil windings 35a terminate in a pair of conductors 43 and 45 (FIG. 5) which respectively connect to a tab 41a projecting from contact plate 41 and the inner end portion 12a of the aforementioned terminal 12. The inner end portion 12a of the terminal 12 is anchored by a rivet 44 (FIG. 8) to an insulating block 46 molded integrally with the housing body 18a. The inner end portion 12a of the terminal 12 has a notch 49 (FIG. 5) receiving a locator pin 51 also molded integrally with the housing body 180. The base of the spring metal body 37a of the reed 37 is sandwiched between an insluating washer 48 and the end leg 50a ofa metal stamping generally indicated by reference numeral 50 forming part of what may be referred to as a terminal bracket assem bly. The end leg 50 a is sandwiched between the base of the reed 37 and an insulating washer 52 which together with the other washer 48 form an assembly held together by a rivet 54 insulated from the end leg 50a of the metal stamping 50 and the spring metal body of the reed 37. The metal stamping 50 has a portion 50b offset from the end leg 50a which portion 50b merges with a bent back portion 50c forming an anchoring leg around which the coil assembly 35 is mounted. The metal stamping 50 has a terminal-forming leg 50d (see FIG. 6) which bears against,and is anchored by a rivet 57 to, a block forming part of the molded housing body 18a. The terminal-forming leg 50d forms the terminal 12' previously described which passes out of the buzzer unit housing through an opening in the side wall 16. The offset portion 50b of the metal stamping 50 has extending therefrom a short anchoring tab 50e passing into a locator hole 59 formed in a boss 61 projecting from the inside of the rear or end wall 24 of the housing body 180.

The operation of the buzzer is as follows. When the coil windings 35a of the coil assembly 35 are deenergized, contact 370 carried by the reed 37 makes contact with the stationary contact 39 to establish electrical continuity between the terminals 12 and 12' via a circuit including the projecting terminal 12, the conductor 45, coil windings 35a, conductor 43, the contact plate 41, stationary contact 39, contact 37c and the metal stamping 50 including the other projecting terminal 12'. The combination striker and magnetic member 37b carried on the end of the reed 37 is initially out of aligriment with the center of the coil windings 35a. When a voltage is connected across the projecting terminals 12-12 of the buzzer unit 2, the coil windings 35a become momentarily energized to generate a magnetic flux which draws the combination striker and magnetic member 37b toward the center of the coil windings which causes the separation of the contacts 370 and 39 and the de-energization of the coil windings 35a. A vibratory action is thus imparted to the reed 37 which repeatedly strikes the nose portion 30 of the vibrating closure wall 18b of the buzzer unit to generate an audible signal.

It should now be apparent that the design of the buzzer unit housing is such that the various buzzer forming parts described can be very easily mounted in position within the housing body 18a and electrically interconnected. Also, the design of the housing 18 is a simple and economical one which provides an overall compact buzzer unit which is insulated to avoid any shock or short circuit hazards.

It should be understood that numerous modifications may be made in the most preferred form of the invention described above without deviating from the broader aspects thereof.

I claim:

1. An electromagnetically-actuated, low energy audio signalling device comprising a housing with electrical terminals accessible at the exterior of the housing, said housing having outer walls with exposed surfaces made of insulating material so noelectrical contact can be made tocomponents inside of the housing except through said electrical terminals, one of said outer walls of said housing being made of metal and forming an electrically insulated vibratable buzzerforming diaphragm, said one vibratable outer wall having an outer coating of an insulating material for electrically isolatingthe metal of the wall from the exterior of the housing, a flexible conductive reed cantilever mounted within said housing and supported thereon, said reed carrying a conductive striker extending adjacent to said vibratable wall of the housing and adapted to strike the same, an electrical contact carried by said reed and adapted to cooperate with an adjacent fixed contact to control an electrical circuit between said electrical terminals, a magnetic field producing coil supported within the housing adjacent said reed and electrically connected-in series with said contacts, 'the flux linkage of said coil and reed when the coil is energized serving to flex said reed to open said contacts, the consequent de-energization of said coil releasing said reed to reclose said contacts, the cyclical flexing of the reed causing said striker repeatedly to strike said vibratable housing wall to produce a vibration of said wall producing an audial signal.

2. The signalling device of claim I wherein said vibratable housing wall is a separate closure wall'for an opening in" the remaining part of the housing through which opening said reed and coil were initially passed into their mounted positions in said housing before the vibratable wall was attached thereto.

3. The signalling device of claim 2 wherein said remaining part of said housing has end and side walls made of molded synthetic plastic material forming a side wall enveloped space within the confines of which the various parts of the signalling device are mounted including said reed and coil, said vibratable wall supported by and bridging the space between the opening defining ends of said housing side walls. i

4. The signalling device of claim 3 wherein said vibratable end wall is an inwardly dished wall which extends inwardly of said housing side walls.

5. An electromagnetically-actuated, low energy audio signalling device comprising a housing having outer walls, one of which forms an electrically insulated vibratable buzzer-forming diaphragm, a pair of electrical terminals at least one of which extends through and projects from both sides of one of said housing walls, said terminals constituting the means for feeding energizing current to the device,a flexible conductive reed cantilever mounted within said housing and said reed carrying a striker extending adjacent to saidvibratable wall of the housing and adapted to strike the same, an electrical contact carried by said reed and adapted to cooperate with an adjacent fixed contact to control an electrical circuit between said electrical terminals, a magnetic field producing coil unit supported within the housing, said one terminal having a projecting portion within the housing upon which said coil unit is at least partially supported, said coil unit being located adjacent said reed and having a coil winding electrically said coil releasing said reed to reclose said contacts, the cyclical flexing of the reed causing said striker repeatedly to strike said vibratable housing wall to produce a vibration of said wall producing an audialsig-nal.

6. The signalling device of claim 5 wherein one or more of said outer walls of said housing other than the vibratable wall thereof includes positioning shoulders for holding and locating portions of said terminals.

7.The signalling device of claim 6 wherein said vibratable end wall is an inwardly dished wall which ex tends inwardly of said housing walls.

8. The signalling device of claim 5 wherein said electrical terminals project through the same outer wall of the housing, and said housing having an outward extension between said terminals which has a retainer forming means for making interlocking engagement with a socket connector to be engaged over said projecting terminals. 7

9. The signalling device of claim 8 wherein another of said outer walls has an outward extension adapted frictionally to fit within a mounting opening in a support wall for the signalling device.

10. The signalling device of claim 5 wherein all of said housing walls have outer surfaces made of insulating material, said vibratable wall having a metal wall with an outer coating of an-insulating material for electrically isolating the metal of the wall from the exterior of the housing.

l l. The signalling device of claim 5 wherein said flexible conductive reed is cantilever mounted within said housing against the portion of one of said terminals projecting from the inner side of said one outer wall so the terminal portion acts as a backing support and makes electrical contact therewith.

12. The signalling device of claim 11 wherein the same one of said terminals acts as a backing support for said reed and as a support for said coil unit.

13. An electromagnetically-actuated, low energy audio signalling device comprising a housing having outer, walls, one of which forms an electrically insulated vibratable buzzer-forming diaphragm, a pair of electrical terminals at least one of which extends through and projects from both sides of one of said housing walls, said terminals constututing the means for feeding energizing current to the device, a flexible conductive reed cantilever mounted within said housing against the portion of said one terminal projecting from the inner side of said one outer wall so the terminal portion acts asa backing support and makes electrical contact therewith, said reed carrying a striker extending adjacent to 7 said vibratable wall of the housing and adapted to strike the same, an electrical contact carried by said reed and adapted to cooperate with an adjacent fixed contact to control an electrical circuit between said electrical terminals, a magnetic field producing coil unit supported within the housing adjacent said reed andhaving a coil winding electrically connected in series with said contacts, said contacts being connected in series with said coil and electrical terminals so the flux linkage of said coil and reed when the coil is. energized thus serving to flex said reed to open said contacts, the consequent deenergization of said coil releasing said reed to reclose said contacts, the cyclical flexing of the reed causing said striker repeatedly to strike said vibratable housing wall to produce a vibration of said wall producing an audial signal.

14. The signalling device of claim 13 wherein said one terminal has a projecting portion within the housing upon which said coil unit is at least partially supported.

K i i I 

1. An electromagnetically-actuated, low energy audio signalling device comprising a housing with electrical terminals accessible at the exterior of the housing, said housing having outer walls with exposed surfaces made of insulating material so no electrical contact can be made to components inside of the housing except through said electrical terminals, one of said outer walls of said housing being made of metal and forming an electrically insulated vibratable buzzer-forming diaphragm, said one vibratable outer wall having an outer coating of an insulating material for electrically isolating the metal of the wall from the exterior of the housing, a flexible conductive reed cantilever mounted within said housing and supported thereon, said reed carrying a conductive striker extending adjacent to said vibratable wall of the housing and adapted to strike the same, an electrical contact carried by said reed and adapted to cooperate with an adjacent fixed contact to control an electrical circuit between said electrical terminals, a magnetic field producing coil supported within the housing adjacent said reed anD electrically connected in series with said contacts, the flux linkage of said coil and reed when the coil is energized serving to flex said reed to open said contacts, the consequent deenergization of said coil releasing said reed to reclose said contacts, the cyclical flexing of the reed causing said striker repeatedly to strike said vibratable housing wall to produce a vibration of said wall producing an audial signal.
 2. The signalling device of claim 1 wherein said vibratable housing wall is a separate closure wall for an opening in the remaining part of the housing through which opening said reed and coil were initially passed into their mounted positions in said housing before the vibratable wall was attached thereto.
 3. The signalling device of claim 2 wherein said remaining part of said housing has end and side walls made of molded synthetic plastic material forming a side wall enveloped space within the confines of which the various parts of the signalling device are mounted including said reed and coil, said vibratable wall supported by and bridging the space between the opening defining ends of said housing side walls.
 4. The signalling device of claim 3 wherein said vibratable end wall is an inwardly dished wall which extends inwardly of said housing side walls.
 5. An electromagnetically-actuated, low energy audio signalling device comprising a housing having outer walls, one of which forms an electrically insulated vibratable buzzer-forming diaphragm, a pair of electrical terminals at least one of which extends through and projects from both sides of one of said housing walls, said terminals constituting the means for feeding energizing current to the device, a flexible conductive reed cantilever mounted within said housing and said reed carrying a striker extending adjacent to said vibratable wall of the housing and adapted to strike the same, an electrical contact carried by said reed and adapted to cooperate with an adjacent fixed contact to control an electrical circuit between said electrical terminals, a magnetic field producing coil unit supported within the housing, said one terminal having a projecting portion within the housing upon which said coil unit is at least partially supported, said coil unit being located adjacent said reed and having a coil winding electrically connected in series with said contacts, said contacts being connected in series with said coil and electrical terminals so the flux linkage of said coil and reed when the coil is energized thus serving to flex said reed to open said contacts, the consequent de-energization of said coil releasing said reed to reclose said contacts, the cyclical flexing of the reed causing said striker repeatedly to strike said vibratable housing wall to produce a vibration of said wall producing an audial signal.
 5. The signalling device of claim 5 wherein one or more of said outer walls of said housing other than the vibratable wall thereof includes positioning shoulders for holding and locating portions of said terminals.
 7. The signalling device of claim 6 wherein said vibratable end wall is an inwardly dished wall which extends inwardly of said housing walls.
 8. The signalling device of claim 5 wherein said electrical terminals project through the same outer wall of the housing, and said housing having an outward extension between said terminals which has a retainer-forming means for making interlocking engagement with a socket connector to be engaged over said projecting terminals.
 9. The signalling device of claim 8 wherein another of said outer walls has an outward extension adapted frictionally to fit within a mounting opening in a support wall for the signalling device.
 10. The signalling device of claim 5 wherein all of said housing walls ave outer surfaces made of insulating material, said vibratable wall having a metal wall with an outer coating of an insulating material for electrically isolating the metal of the wall from the exterior of the housing.
 11. The signalling device of claim 5 wherein said flexible conductive reed is cantilever mounted within said housing against the portion of one of said terminals projecting from the inner side of said one outer wall so the terminal portion acts as a backing support and makes electrical contact therewith.
 12. The signalling device of claim 11 wherein the same one of said terminals acts as a backing support for said reed and as a support for said coil unit.
 13. An electromagnetically-actuated, low energy audio signalling device comprising a housing having outer walls, one of which forms an electrically insulated vibratable buzzer-forming diaphragm, a pair of electrical terminals at least one of which extends through and projects from both sides of one of said housing walls, said terminals constututing the means for feeding energizing current to the device, a flexible conductive reed cantilever mounted within said housing against the portion of said one terminal projecting from the inner side of said one outer wall so the terminal portion acts as a backing support and makes electrical contact therewith, said reed carrying a striker extending adjacent to said vibratable wall of the housing and adapted to strike the same, an electrical contact carried by said reed and adapted to cooperate with an adjacent fixed contact to control an electrical circuit between said electrical terminals, a magnetic field producing coil unit supported within the housing adjacent said reed and having a coil winding electrically connected in series with said contacts, said contacts being connected in series with said coil and electrical terminals so the flux linkage of said coil and reed when the coil is energized thus serving to flex said reed to open said contacts, the consequent de-energization of said coil releasing said reed to reclose said contacts, the cyclical flexing of the reed causing said striker repeatedly to strike said vibratable housing wall to produce a vibration of said wall producing an audial signal.
 14. The signalling device of claim 13 wherein said one terminal has a projecting portion within the housing upon which said coil unit is at least partially supported. 